A Cost-effective and Greener Process for 3-methyl-5-phenylpentanol (Mefrosol)

Mefrosol is an industrially important perfumery chemical that gives freshness and volume in both floral and citrus fragrances. Due to high demand and no indigenous process available, India imports this perfumery chemical in large quantity, primarily from China. At CSIR-CSMCRI, we have developed a chemical process for Mefrosol at 1 Kg level in > 90% yield and > 98% purity. The process consists of two synthetic steps: Step I: Condensation between benzaldehyde and isoprenol leading to a mixture of dihydropyran derivatives (rosyranes); Step II: Catalytic hydrogenation of the resulting mixture. The process employs cheap and recyclable catalysts, commercial grade reagents and solvents without further purification, giving high yield and industrially relevant purity. Compared to the conventional techniques, the CSMCRI process is much greener in terms of both waste management and the use of benign ingredients and allows for reducing the cost tentatively 20-25% of the existing market price. The complete basic engineering package (BEP) is ready for commercialization, and the demonstration at an industry site can be performed at 1 Kg per batch scale. This is the first indigenous process for Mefrosol in India and when commercialized, we anticipate that the process may lead to the import substitution of Mefrosol.

Mefrosol is an industrially important perfumery chemical that is primarily imported from abroad. Thus, perfumery industries are the target sector for this product.

• Currently no indigenous process for Mefrosol is available in India. CSMCRI’s Technology is the first chemical process for the production of Mefrosol with a high yield and industrially relevant purity.
• The present process is very much clean giving water as the only by-product resulting in excellent yield and purity of the desired product Mefrosol.
• The present process is cost-competitive as it utilizes commercial grade starting materials, reagents and solvents.
• The present process avoids any purification by chromatographic separation.
• The present process is easily scalable up to 1 Kg level.
• The present process is consistently reproducible and hence, reliable to industrial applications.